Thomas Aquinas's account of the semantics of names is based on two fundamental distinctions: the distinction between a name's mode of signifying and the signified object, and that between the cause and the goal of a name's signification, i.e. that from which a name was instituted to signify and that which a name actually signifies. Thomas endows names with a two-layer signification: names are introduced into language to designate primarily conceptions of extramental things and secondarily the particular extramental things referred to by such conceptions. On such a `conceptualistic' account of names' signification, Thomas recognizes that a generic acquaintance with external things is a sufficient condition for imposing names to signify things. Following this intuition, Thomas at times dwells on the role that pragmatic factors such as the common usage of names by a linguistic community ( usus loquendi ) and the speakers' intention ( intentio loquentium ) play in explaining both the formation and semantic function of conventional language. This paper will focus on what Thomas had to say about such factors